Assuming you set k=2 and did the kmeans like you said and is shown in this example, I don't know what you want to do next. You haven't said. The most typical thing to do next is to call bwlabel() or bwconncomp() followed by regionprops to make various measurements (such as area) on the regions. I can be more specific if you get more specific.

I thought you had already done that part because you said " have converted into hsv colour space,with k=2" and you showed an image that you had created. Converted is past tense, meaning that it happened in the past. Was that wrong? Did you not convert (classify) the image yet and so you needed Thorsten's code to do it for you?

Assuming you set k=2 and did the kmeans like you said and is shown in this example, I don't know what you want to do next. You haven't said. The most typical thing to do next is to call bwlabel() or bwconncomp() followed by regionprops to make various measurements (such as area) on the regions. I can be more specific if you get more specific.